In the present human society that is driven by digital information, various types of personal information are digitalized in electronic products for transmission, transfer and recording. Through the use of cards, communication of information is more convenient. Card types that are widely used in people's daily life include cardholder's proprietary cards, such as debit cards, credit cards and the like issued by banks; prepaid cards that are equivalent to securities; and identity cards such as driver's license, health insurance card, passport and the like.
Most of the proprietary cards and security-equivalent cards are provided on a back side with a magnetic stripe, into which required information is written. And, information magnetically stored in the stripe can be read with an automatic card reader, such as an automatic teller's machine, or other manual card readers for performing subsequent procedures.
To stop easy production of counterfeit cards that cause cardholders' loss in property, a design of forming a magnetic field generator inside the cards for changing the magnetic field magnitude of the magnetic cards has been developed. Please refer to FIGS. 1 and 2. A first conventional magnetic field generator 1 provided in magnetic cards includes a substrate material 10, on a surface thereof a plurality of bonding pads 11, a plurality of connection pads 12, a plurality of bonding wires 13 and a core material member 14 are arranged. The bonding pads 11 are arrayed on the surface of the substrate material 10 in rows and columns. The connection pads 12 are respectively connected at an end to a first bonding pad 11 and at another end to a second bonding pad 11 that is located at a column the same as the first bonding pad 11 but at a row different from the first bonding pad 11 and is therefore closest to the first bonding pad 11. The bonding wires 13 are bonded at two opposite ends to two of the bonding pads 11 that are located at two different rows and columns, such that the bonding wires 13 are extended in a direction oblique to the connection pads 12 to be arc-shaped each. The core material member 14 is arranged between the connection pads 12 and the bonding wires 13.
To form the first conventional magnetic field generator 1, the bonding wires 13 must be precisely bonded to connect at respective two ends to two boding pads 11 that are located at different rows and columns. Therefore, equipment with relatively high precision for bonding wires is required in the manufacturing process. In addition, the bonding wires 13 are subject to a certain probability of breaking in subsequent fabrication procedures. That is, the first conventional magnetic field generator 1 needs improvement in terms of its manufacturing cost and yield rate.
FIG. 3 shows a second conventional magnetic field generator 2 provided in magnetic cards. The second conventional magnetic field generator 2 includes a first substrate material 20, a plurality of first bonding pads 21, a plurality of first connection pads 22, a second substrate material 23, a plurality of second bonding pads 24, a plurality of second connection pads 25, a plurality of connection material members 26, and two core material members 27. The first bonding pads 21 are arranged on a surface of the first substrate material 20, and the first connection pads 22 are respectively connected at two opposite ends to between two of the first bonding pads 21. The second boding pads 24 are arranged on a surface of the second substrate material 23, and the second connection pads 25 are respectively connected at two opposite ends to between two of the second bonding pads 24. And, each of the first bonding pads 21 on the first substrate material 20 is connected to one second bonding pad 24, which is located on the second substrate material 20 at a position corresponding to the first bonding pad 21, via a connection material member 26.
The second conventional magnetic field generator 2 formed of the mutually connected first substrate material 20 and second substrate material 23 is improved compared to the first conventional magnetic field generator 1, because electrical circuits are formed on the magnetic field generator 2 in a different manner to overcome the problem of easily breaking bonding wires. However, since the two substrate materials are independently fabricated, more manufacturing procedures are needed and material cost is largely increased.